This invention relates to a new and improved sequencing disk with a generally cup-shaped means thereon for improving movement of the sequencing disk, fix the stem relative to the sequencing disk, and to filter the incoming fluid and providing a check valve function.
In the past many problems have been encountered in providing functionally operable sequencing valve sealing means at both low and high fluid flow rates. The E. Haggard U.S. Pat. No. 3,369,565 discloses a sequencing valve having an integrally mounted check valve. It will be obvious to those skilled in the art that the sequencing valve of U.S. Pat. No. 3,369,565 can operate in response to supply fluid delivered through the valve inlet and distributed out of a plurality of outlets. The main sealing means reciprocates and rotates during its cyclic operation in a well known manner. The Miller U.S. Pat. No. 3,785,391 shows a resilient variable flow check valve in a sequencing valve. A variable flow device is shown by the C. Kah, Jr., et al, U.S. Pat. No. 3,524,470 incorporating a flap valve in the valve member.
Thus, previously designed fluid flow operated sequencing valves required a significant amount of fluid flow through the valve to properly operate the sequencing valve. Obviously, if a high fluid flow rate is to pass through the valve, the valve design is not complex. When a large check port area is used in the sequencing valve to accomodate large fluid flow rates, it becomes difficult to sequence the disk by use of the check valve when only a low fluid flow rate passes through the valve. The large outer perimeter of the check valve element immediately creates a large opening area with very small downward movement of the check valve. A large fluid flow rate is therefore required to move the check valve element and disk downwardly any substantial distance to achieve complete cycling. This has also been found true in variable flow check devices such as in the Miller U.S. Pat. No. 3,785,391. Accordingly, prior art fluid flow operated sequencing valves with check valve means have been limited to a rather small range of fluid flow rates.